Significance of Body Mass Index for Postoperative Outcomes after Lung Cancer Surgery in Elderly Patients.

Abstract

Although the frequency of elderly patients undergoing surgery for lung cancer has been increasing, indications for surgery in elderly patients are still controversial. Low body mass index is a significant predictor of poor prognosis in elderly patients with various medical conditions. Then, we examined the long-term outcome of elderly patients who had undergone thoracic surgery for lung cancer, focusing especially on body mass index. Between January 2004 and March 2011, 1673 patients with lung cancer underwent surgical resection at our institution. Among these patients, we retrospectively examined 158 patients aged 80 years or older. Perioperative morbidity and mortality rates were 41.8 and 1.3%, respectively. Among 149 patients who were completely followed up, 80 patients (53.7%) died. The overall postoperative survival rates at 3 and 5 years were 66.9 and 49.9%, respectively. Univariate analysis demonstrated that sex (female), smoking index (pack-years <20), histology (non-squamous cell carcinoma), pathological stage (stage I) and BMI (within normal BMI) were statistically significant factors associated with better outcome. Multivariate analysis revealed that patients with a low (<18.5 kg/m²) or high (≥25 kg/m²) body mass index had a significantly and poorer prognosis than patients with a normal body mass index. Body mass index is a more useful prognostic factor than other clinical factors including pathological stage in elderly patients. Because elderly patients with low and high body mass index have a significant poor prognosis, surgeons and pulmonologist should take this into account when consider surgical indication for such elderly patients.